/**
 * Copyright 1999-2015 dangdang.com.
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * </p>
 */

package com.vip.saturn.job.utils;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import com.google.common.base.Joiner;
import com.google.common.base.Strings;

/**
 * 分片项工具类.
 * 
 * 
 */
public final class ItemUtils {

	private static final String DELIMITER = ",";

	/**
	 * 根据分片项字符串获取分片项列表.
	 * 
	 * @param itemsString 分片项字符串
	 * @return 分片项列表
	 */
	public static List<Integer> toItemList(final String itemsString) {
		if (Strings.isNullOrEmpty(itemsString)) {
			return Collections.emptyList();
		}
		String[] items = itemsString.split(DELIMITER);
		List<Integer> result = new ArrayList<>(items.length);
		for (String each : items) {
			int item = Integer.parseInt(each);
			if (!result.contains(item)) {
				result.add(item);
			}
		}
		return result;
	}

	/**
	 * 根据分片项列表获取分片项字符串.
	 * 
	 * @param items 分片项列表
	 * @return 分片项字符串
	 */
	public static String toItemsString(final List<Integer> items) {
		return items.isEmpty() ? "" : Joiner.on(ItemUtils.DELIMITER).join(items);
	}
}
